In thermal dye sublimation printing, it is generally well known to render images by heating and pressing one or more donor materials such as a colorant (e.g., a dye) or other coating against a receiver medium having a colorant receiving layer. The heat is generally supplied by a thermal print head having an array of heating elements. The donor materials are typically provided in sized donor patches on a movable web known as a donor ribbon. The donor patches are organized on the ribbon into donor sets, each set containing all of the donor patches that are to be used to record an image on the receiver web. For full color images, multiple color dye patches can be used, such as yellow, magenta, and cyan donor dye patches. Arrangements of other color patches can be used in like fashion within a donor set. Additionally, each donor set can include an overcoat or sealant layer.
Thermal printers offer a wide range of advantages in photographic printing, including the provision of truly continuous tone scale variation and the ability to deposit, as a part of the printing process a protective overcoat layer to protect the images formed thereby from mechanical and environmental damage. Accordingly, many photographic kiosks and home photo printers currently use thermal printing technology.
It is advantageous for a thermal printer to adjust the operation of the thermal print head depending on the type of receiver media that is loaded in the thermal printer. However, current methods of determining the type of receiver media have a significant drawback because they do not determine the type of receiver media directly. In current roll feed thermal printers, the only way to determine receiver media type is to read the bar code label located on the donor media roll spool. This requires the printer's bar code reader to scan the donor media spool at the outset, prior to printing. The bar code pattern on the donor media spool theoretically corresponds with the particular type of receiver media that should be used in conjunction with the certain type of donor media. The bar code is processed by the printer's firmware to determine if the media type is correct, what size media is loaded, and which look-up table (LUT) should be used for the media type.
Donor media and receiver media are generally sold and implemented as kits—in other words, as complementary pairs—to optimize printing quality. Using donor media from one kit with receiver media from another kit may result in markedly reduced printing quality. Current methods determine the type of donor dye supply roll and then assume that the receiver media is a type that is appropriate for the donor dye supply roll. Thus, the problem with the media type detection process currently implemented in industry is that the receiver media type is being determined solely based on the donor dye supply roll, which may not necessarily align with the receiver type that would optimize printing quality.
An improvement needs to be made so that both donor media type and receiver media type can be determined without having to implement any new printer hardware to achieve complete backwards compatibility.